Dual-aperture zoom digital camera with automatic adjustable tele field of view

ABSTRACT

Digital camera comprising an upright Wide camera configured to provide a Wide image with a Wide image resolution and a folded Tele camera configured to provide a Tele image with a Tele image resolution higher than the Wide image resolution, the Wide and Tele cameras having respective Wide and Tele fields of view FOV W  and FOV T  and respective Wide and Tele image sensors, the digital camera further comprising a rotating OPFE operative to provide a folded optical path between an object or scene and the Tele image sensor, wherein rotation of the OPFE moves FOV T  relative to FOV W . In some embodiments, a rectangular FOV T  is orthogonal to a rectangular FOV W . When included in a host device having a user interface that displays FOV T  within FOV W , the user interface may be used to position FOV T  relative to FOV W , scan FOV T  across FOV W  and acquire, store and display separate Wide and Tele images, composite Wide plus Tele images and stitched Tele images. The positioning of FOV T  within FOV W , can be done automatically (autonomously) by continuously tracking an object of interest.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/699,577 filed Nov. 30, 2019 (now allowed), which was a continuationof U.S. patent application Ser. No. 15/525,059 filed May 6, 2017 (nowissued as U.S. patent Ser. No. 10/578,948), which was a 371 applicationfrom international patent application PCT/IB2016/057366 filed Dec. 5,2016 and claims priority from U.S. Provisional Patent Applications No.62/272,367 filed on Dec. 29, 2015 and 62/361,150 filed on Jul. 12, 2016,both of which are expressly incorporated herein by reference in theirentirety.

FIELD

Embodiments disclosed herein relate in general to digital cameras and inparticular to thin zoom digital cameras.

BACKGROUND

Host devices or “personal computing and/or communication devices” (suchas smartphones) having two back cameras (also referred to as“dual-camera” or “dual-aperture camera”) are known, see e.g. U.S. Pat.No. 9,185,291. The two back cameras have two image sensors (or simply“sensors”) operated simultaneously to capture an image, and have lenseswith different focal lengths. Even though each lens/sensor combinationis aligned to look in the same direction, each will capture an image ofthe same scene but with two different fields of view (FOV).

Dual-aperture zoom cameras in which one camera has a “Wide” FOV(FOV_(W)) and the other has a narrow or “Tele” FOV (FOV_(T)) are alsoknown, see e.g. U.S. Pat. No. 9,185,291. The cameras are referred torespectively as Wide and Tele cameras that include respective Wide andTele sensors. These sensors provide respectively separate Wide and Teleimages. The Wide image captures FOV_(W) and has lower spatial resolutionthan the Tele image that captures FOV_(T). As used herein, “FOV” isdefined by the tangent of the angle between a line crossing the lens andparallel to the lens optical axes and a line between the lens and anyobject that is captured on the respective image corner. The images maybe merged (fused) together to form a composite image. In the compositeimage, the central portion is formed by combining the relatively higherspatial resolution image taken by the lens/sensor combination with thelonger focal length, and the peripheral portion is formed by aperipheral portion of the relatively lower spatial resolution imagetaken by the lens/sensor combination with the shorter focal length. Theuser selects a desired amount of zoom and the composite image is used tointerpolate values from the chosen amount of zoom to provide arespective zoom image. Hereinafter, the use of “resolution” in thisdescription refers to image spatial resolution, which is indicative tothe resolving power of a camera as determined by the lens focal length,its aperture diameter and the sensor pixel size.

Dual-aperture cameras in which one image (normally the Tele image) isobtained through a folded optical path are known, see e.g. co-inventedand co-owned U.S. patent application Ser. No. 14/455,906, which teacheszoom digital cameras comprising an “upright” (with a direct optical axisto an object or scene) Wide camera and a “folded” Tele camera, see alsoFIG. 2B below. The folded camera has an optical axis substantiallyperpendicular (orthogonal) to an optical axis of the upright camera. Thefolded Tele camera may be auto-focused and optically stabilized bymoving either its lens or by tilting an optical path folding(reflecting) element (e.g. a prism or mirror and referred to also as“OPFE”) inserted in an optical path between its lens and a respectivesensor. For simplicity, the optical path folding element is referred tohereinafter in this description generically as “prism”, with theunderstanding that the term may refer to any other optical path folding(reflecting) element that can perform the function of folding an opticalpath as described herein.

For example, PCT patent application PCT/IB2016/056060 titled“Dual-aperture zoom digital camera user interface” discloses a userinterface for operating a dual-aperture digital camera included in hostdevice, the dual-aperture digital camera including a Wide camera and aTele camera, the user interface comprising a screen configured todisplay at least one icon and an image of a scene acquired with at leastone of the Tele and Wide cameras, a frame defining FOV_(T) superposed ona Wide image defined by FOV_(W), and means to switch the screen fromdisplaying the Wide image to displaying the Tele image. The userinterface further comprises means to switch the screen from displayingthe Tele image to displaying the Wide image. The user interface mayfurther comprise means to acquire the Tele image, means to store anddisplay the acquired Tele image, means to acquire simultaneously theWide image and the Tele image, means to store and display separately theWide and Tele images, a focus indicator for the Tele image and a focusindicator for the Wide image.

Object recognition is known and describes the task of finding andidentifying objects in an image or video sequence. Many approaches havebeen implemented for accomplishing this task in computer vision systems.Such approaches may rely on appearance based methods by using exampleimages under varying conditions and large model-bases, and/or on featurebased methods comprising of a search to find feasible matches betweenobject features and image features, e.g., by using surface patches,corners and edges detection and matching. Recognized objects can betracked in preview or video feeds using an algorithm for analyzingsequential frames and outputting the movement of targets between theframes.

The problem of motion-based object tracking can be divided into twoparts:

(1) detecting moving objects in each frame. This can be done either byincorporating an object recognition algorithm for recognizing andtracking specific objects (e.g., human face) or, for example, bydetecting any moving object in a scene. The latter may incorporate abackground subtraction algorithm based on Gaussian mixture models withMorphological operations applied to the resulting foreground mask toeliminate noise. Blob analysis can later detect groups of connectedpixels, which are likely to correspond to moving objects.

(2) associating the detections corresponding to the same object overtime, e.g., using motion estimation filters such as the Kalman filter.

SUMMARY

In exemplary embodiments, there are provided digital cameras comprisingan upright Wide camera configured to provide a Wide image with a Wideimage resolution, the Wide camera comprising a Wide image sensor and aWide lens with a Wide field of view (FOV_(W)); a folded Tele cameraconfigured to provide a Tele image with a Tele image resolution higherthan the Wide image resolution, the Tele camera comprising a Tele imagesensor and a Tele lens with a Tele field of view (FOV_(T)); and arotating OPFE (e.g. prism) operative to provide a folded optical pathbetween an object or scene and the Tele sensor, wherein rotation of theprism moves FOV_(T) relative to FOV_(W).

In an embodiment, the Wide and Tele image sensors have a substantiallyrectangular shape defined by a respective height dimension and arespective width dimension and are in orthogonal planes and with theirrespective height dimensions orthogonal to each other such that FOV_(T)is rotated at 90 degrees to FOV_(W).

In an embodiment, the movement of FOV_(T) relative to FOV_(W) isperformed in a scanning mode that provides a plurality ofpartially-overlapping or adjacent non-overlapping Tele FOVs withinFOV_(W).

In an embodiment, the prism rotation has a range of up to ±15 degreesaround a zero prism position in which FOV_(T) is centric to FOV_(W).

In an embodiment, the digital camera may be included in a host devicehaving a user interface for operating the digital camera, the userinterface comprising a screen configured to display at least one iconand an image of the object or scene acquired with at least one of theTele and Wide cameras and to display a frame defining FOV_(T) withinFOV_(W). The host device may have a user interface for operating thedigital camera, the user interface comprising a screen configured todisplay at least one icon and an image of the object or scene acquiredwith at least one of the Tele and Wide cameras and to display a framedefining FOV_(T) within FOV_(W). In an embodiment, the user interfacemay further comprise means for moving FOV_(T) relative to FOV_(W). In anembodiment, the user interface may further comprise means for scanningFOV_(T) across FOV_(W). In an embodiment, the user interface may furthercomprise means for switching the screen from displaying the Wide imageto displaying the Tele image. In an embodiment, the user interface mayfurther comprise means to acquire the Tele image. In an embodiment, theuser interface may further comprise means to acquire simultaneously theWide image and the Tele image.

In an embodiment, the user interface may further comprise means toautomatically (autonomously) move the FOV_(T) relative to FOV_(W) totrack object of interest. In such cases, the camera may also be referredto as an “autonomous” camera.

In an embodiment, the user interface may further comprise means toacquire video streams of the Wide and Tele camera simultaneously.

In an embodiment, Tele images representing are plurality of adjacentnon-overlapping Tele FOVs are stitched together to form a stitched Teleimage used in the fusion with the Wide image.

In an embodiment, at least one Tele image includes a plurality ofconsecutive Tele images stitched together to form a stitched Tele imageused in a fusion procedure with the Wide image to provide a compositeimage.

In an embodiment, the Wide and Tele images or video streams can be fused(or combined or stitched) on the device or in a cloud environment(referred to simply as “cloud”).

In an embodiment, the digital camera is further configured to form acomposite video stream in which each frame is based on either aprocessed Wide image or a processed Tele image, the processed Wide andTele images acquired during the autonomous FOV_(T) tracking.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting examples of embodiments disclosed herein are describedbelow with reference to figures attached hereto that are listedfollowing this paragraph. Identical structures, elements or parts thatappear in more than one figure are generally labeled with a same numeralin all the figures in which they appear. The drawings and descriptionsare meant to illuminate and clarify embodiments disclosed herein, andshould not be considered limiting in any way.

FIG. 1A shows schematically an image reflecting the Wide FOV of a scene;

FIG. 1B shows schematically an image reflecting the Tele FOV of thescene in FIG. 1A;

FIG. 2A shows schematically a dual-aperture camera comprising a firstupright camera and a second folded camera, with a prism folding anoptical path to the folded camera in a zero position;

FIG. 2B shows a composite image obtained with a dual-aperture camera asin FIG. 2A, with the Tele FOV resulting from the zero position of theprism;

FIG. 3 shows schematically an arrangement enabling tilt of a prism in afolded optical path;

FIG. 4A shows schematically the dual-aperture camera of FIG. 2A with theprism rotated to a first position;

FIG. 4B shows a composite image obtained with a dual-aperture camera asin FIG. 4A, with the Tele FOV resulting from the first prism position;

FIG. 5A shows schematically the dual-aperture camera of FIG. 2A with theprism rotated to a second position;

FIG. 5B shows a composite image obtained with a dual-aperture camera asin FIG. 5A, with the Tele FOV resulting from the second prism position;

FIG. 6A shows schematically a dual-aperture camera comprising a firstupright camera with a sensor rotated by 90 degrees relative to that inthe camera of FIG. 2A and with a prism folding an optical path to afolded camera in a zero position;

FIG. 6B shows a composite image obtained with a dual-aperture camera asin FIG. 6A, with the Tele FOV resulting from the zero position of theprism;

FIG. 7A shows schematically the dual-aperture camera of FIG. 6A with theprism rotated to a first position;

FIG. 7B shows a composite image obtained with a dual-aperture camera asin FIG. 7A, with the Tele FOV resulting from the first prism position;

FIG. 8A shows schematically the dual-aperture camera of FIG. 6A with theprism rotated to a second position;

FIG. 8B shows a composite image obtained with a dual-aperture camera asin FIG. 8A, with the Tele FOV resulting from the second prism position;

FIG. 9A shows a smartphone and user interface incorporating adual-aperture camera with Tele FOV positioning capability disclosedherein in a zero, centered position on the smartphone screen;

FIG. 9B shows the smartphone and user interface of FIG. 9A with the TeleFOV moved to a down position within the screen;

FIG. 9C shows the smartphone and user interface of FIG. 9A with the TeleFOV moved to an up position within the screen;

FIG. 9D shows the smartphone and user interface of FIG. 9A with the TeleFOV rotated by 90 degrees relative to the Wide FOV and moved to a rightposition within the screen;

FIG. 9E shows the smartphone and user interface of FIG. 9A with the TeleFOV rotated by 90 degrees relative to the Wide FOV and moved to a leftposition within the screen;

FIG. 10 shows a smartphone and user interface as in FIG. 9D or 9E usedin a scanning mode of the Tele FOV.

FIG. 11A shows a smartphone and user interface incorporating adual-aperture camera with automatic Tele FOV tracking disclosed hereinwith a first Tele FOV position on the smartphone screen;

FIG. 11B shows the smartphone and user interface of FIG. 11A with asecond Tele FOV position on the smartphone screen;

FIG. 11C shows the smartphone and user interface of FIG. 11A with athird Tele FOV position on the smartphone screen.

DETAILED DESCRIPTION

FIG. 1A shows schematically an image (or frame of a video stream) 102reflecting the Wide FOV of a scene 106. FIG. 1B shows schematically animage (or frame of a video stream) 104 reflecting the Tele FOV of scene106. Only part of the scene of FIG. 1A is seen in FIG. 1B. The twoimages or video streams are obtained simultaneously with a dual-aperturecamera having an upright Wide camera and a folded Tele camera of thetype for example disclosed in U.S. patent application Ser. No.14/455,906. The two cameras may, for example, be two back camerasincluded in a smartphone or in another personal communication device.

FIG. 2A shows schematically a dual-aperture camera 200 comprising afirst upright camera 202 and a second folded camera 204. An XYZcoordinate system as shown is used in the description of this and allfollowing “camera” drawings. For example, upright camera 202 is a Widecamera that includes a Wide lens assembly (or simply “lens”) 206 with anoptical axis 207, and a Wide sensor 208. For example, folded camera 204is a Tele camera that includes a Tele lens 210 with an optical axis 211,and a Tele sensor 214. An OPFE (e.g. prism) 212 may be part of thefolded Tele camera or may be a separate element that folds an opticalpath parallel to axis 207 into an optical path parallel to axis 211 intothe Tele lens. The Wide and Tele sensors lie in respective orthogonalplanes, respectively the XZ plane and the XY plane. For example, theWide and Tele sensors are substantially rectangular with respectiveheight (H) and width (W) dimensions. Thus, Wide sensor 208 has a heightH_(W) and a width W_(W) and Tele sensor 214 has a height H_(T) and awidth W_(T). The H/W ratio in both sensors is typically (although notnecessarily) 9/16 or 3/4. In the folded camera, positioning of sensor214 with its height in the Y direction is advantageous in that it allowsa smaller host device (e.g. a smartphone) thickness. In camera 200 inFIG. 2A (as well as cameras 200 in FIGS. 3, 4A and 5A), the widthdimensions of sensors 208 and 214 are parallel to each other and to theX-axis.

The operation of a camera such as camera 200 is described in more detailin U.S. patent application Ser. No. 14/455,906. In particular, the prismcan perform a tilt (rotation) movement 216 around the X-axis as shown.The rotation motion may be caused by a stepping motor 302 shownschematically in FIG. 3. The prism rotation angle may range between −15degrees and +15 degrees around a “zero” position (see below),corresponding to ±30 degrees FOV_(T) shift. Cameras 202 and 204 are usedfor example to take respectively the Wide and Tele images of FIGS. 1Aand 1B.

FIG. 2B shows an image 230 identical with Wide image 102 with a frame232 that indicates the position of the Tele image FOV. The camera canhave high resolution in this framed FOV either by fusing the Wide andTele images or by capturing and saving the Tele image. For referencepurposes, the position of the prism that causes the Tele FOV andresulting image to be centric to the Wide FOV and Wide image is calledhere for example and in a non-limiting way a “zero” position of theprism.

The rotation of prism 212 around the X-axis moves the Tele FOV relativeto the Wide FOV, causing other portions of scene 106 to become a “Teleimage” with higher resolution. Thus, FIG. 4A shows prism 212 rotatedcounter-clockwise (as indicated by a curved arrow 402 when viewed in the−X direction) around the X-axis from its zero position to a new, firstposition. The counter-clockwise rotation causes the Tele FOV, indicatedby frame 232, to move to a new, “down” position relative to the Wide FOVindicated by frame 230. FIG. 5A shows prism 212 rotated clockwise (asindicated by a curved arrow 502 when viewed in the −X direction) aroundthe X-axis from its zero position to a new, second position. Theclockwise rotation causes the Tele FOV, indicated by frame 232, to moveto another new, “up” position relative to the Wide FOV indicated byframe 230. While FIGS. 4A, 4B, 5A and 5B show two discrete prismrotation movements and two discrete Tele FOV positions relative to theWide FOV, there is clearly an entire range of practically continuouspositions that the Tele FOV may occupy, depending on the degree anddirection of prism rotation.

As mentioned, in FIGS. 2A, 3, 4A and 5A, both Wide sensor 208 and Telesensor 214 are positioned with their longer side (“width”) in the Xdirection. Their shorter side (“height”) is in the Z direction forsensor 208 and in the Y direction for sensor 214. FIG. 6A showsschematically a dual-aperture camera 200′ comprising an upright camera206 with a Wide sensor 208′ rotated by 90 degrees relative to sensor 208in camera 206 of FIG. 2A. As also shown in FIGS. 7A and 8A, Wide sensor208′ now has its height in the X direction and its width in the Zdirection. Note that W_(W) is now also orthogonal to the H_(T). This 90degree in-plane rotation of the Wide sensor provides certain advantagesin terms of the positioning and movement of FOV_(T) relative to FOV_(W),and consequently in terms of the capture, processing and display of Teleand Wide images. One major advantage is that a larger percentage ofFOV_(W) can have high resolution by setting a prism rotation angle. FIG.6B shows schematically the position of FOV_(T) 232′ (now rotated by 90degrees relative to FOV_(W) 230) in a centered position caused by a zeroposition of prism 212, after the camera itself was rotated by 90 degrees(not shown) compared to the camera of FIG. 2B.

FIG. 7A shows schematically the dual-aperture camera of FIG. 6A withprism 212 rotated counter-clockwise (as indicated by a curved arrow 702when viewed in the −X direction) around the X-axis from its zeroposition to a new position. As shown in FIG. 7B, this prism rotationcauses Tele FOV 232′ to move to a “right” position relative to the WideFOV. FIG. 8A shows prism 212 rotated clockwise (as indicated by a curvedarrow 802 when viewed in the −X direction) around the X-axis from itszero position to a second position, As shown in FIG. 8B, this prismrotation causes Tele FOV 232′ to move to a “left” position relative tothe Wide FOV. While FIGS. 7A, 7B, 8A and 8B show two discrete prismrotation movements and two discrete Tele FOV positions relative to theWide FOV, there is clearly an entire range of practically continuouspositions that the Tele FOV may occupy, depending on the degree anddirection of prism rotation.

Note that a similar FOV_(T) relative positioning effect to thatdescribed above may be obtained by in-plane rotating Tele sensor 214 by90 degrees and by leaving Wide sensor 208 unchanged from its originalposition in FIG. 2A. However, the positioning of sensor 214 with W_(T)in the Y direction may disadvantageously increase a camera height (andtherefore a host device thickness).

When a dual-aperture camera described above is included for example in asmartphone, the Tele image (i.e. the part of scene 106 viewed andacquired by the Tele camera) is bound by a frame 932 visible on thesmartphone screen. FIG. 9A shows an exemplary smartphone 900 thatincludes on a back side (not shown) a Wide camera and a Tele camera asin FIG. 2A or 6A. The Wide and Tele cameras have known fields of viewwith a known ratio M=FOV_(T)/FOV_(W) between them. In general, M mayhave any value between 1/4 and 3/4. For example, M may have values of1/2, 9/16 or 3/4. Consequently, frame 932 includes almost exactly theimage seen by FOV_(T) and has a size that is a fraction M of the entirescreen (which includes the image seen by FOV_(W)). Note that for cameraconfiguration as the one shown in FIG. 6A and for Wide and Tele imagesensors with 4:3 aspect ratio, selecting M=3/4 will result in FOV_(T)that will overlap the short dimension of FOV_(W) in its entirety andwill enable complete scanning of the Wide FOV by tilting the prism. Thesame argument is applicable for image sensors having 16:9 aspect ratiowith M=9/16.

In still mode, scene 106 is acquired by both cameras, with the Widecamera providing the entire image seen (i.e. the Wide image) and theTele camera providing the part of scene 106 bound by frame 932.Smartphone 900 further includes, on a front side opposite to the backside, a screen or display 902 displaying a view of scene 106. Screen 902may display icons or text “A”, “B”, “C”, etc., that provide indicationsand/or are selectable to perform various operations of the phone and/orthe cameras. Such icons or text may be indicative of flash setting,video or stills selection, back or front camera selection, etc. Thesquare boxes surrounding “A”, “B” and “C” are merely illustrative andmay have different shape or be removed altogether in some cases. Notethat the fact that only three icons are shown is not meant to belimiting, and that more or fewer icons may be displayed and/orselectable at any time during or prior to image acquisition by thecameras and/or during display of acquired images. In an embodiment ofthe dual-aperture camera as in FIG. 2A, the “zero” position of the prismprovides the composite image seen in FIG. 9A, where frame 932 iscentered on the screen.

In various embodiments and as described in more detail inPCT/IB2016/056060, smartphone 900 may have a user interface thatincludes a single camera icon (or “button”) 908 and a “two-camera”button 910. The two-camera button may appear on the screen when the FOVof the scene (FOV_(scene)) is greater or equal to FOV_(T). As describedin detail in PCT/IB2016/056060, the user interface displays visually thealmost exact FOV_(T) and enables simple acquisition of the image withinFOV_(T), thereby providing a Tele image with the highest resolutionenabled by the Tele camera. The user interface also enables simultaneousacquisition (with a single input through the user interface, i.e. usingtwo-camera button 910) of a Wide image and a Tele image. Image fusion ofthe Wide and Tele images or video streams can take place on thecapturing device or in a cloud environment.

The present inventors have determined that, advantageously, a userinterface as described above can be used to “drag” frame 932 (andFOV_(T)) on screen 902 to bring different parts of the scene intoFOV_(T). That is, the dragging of frame 932 is translated into rotationof the “folded” path prism, such that the higher resolution Tele image“moves” to different parts of the scene. The dragging may be performedby a firm touch of the screen by a finger 920 and movement of the fingeracross the screen. In FIG. 9A, the finger touches the screen in thegeneral area of “zero” positioned (centered) frame 932. The finger maydrag the frame (and FOV_(T)) to a “down” position as in FIG. 9B, to an“up” position as in FIG. 9C, or to any intermediate position (not shown)between the down and up positions. The touch and drag actions arerelayed to a camera controller (not shown), which, in turn, controls theprism movement. The dragging of frame 932 to the down position in FIG.9B, indicated schematically by an arrow 934, is equivalent to rotationof the prism to its position in FIG. 4A. The dragging of frame 932 tothe up position in FIG. 9C is equivalent to rotation of the prism to itsposition in FIG. 5A. Similarly, with a dual-aperture camera with a 90degree rotated Wide sensor as in FIGS. 6A-8A, a frame 932′ (now alsorotated by 90 degrees relative to frame 932 in FIGS. 9A-9C) may bedragged from a zero position to a “right” position as in FIG. 9D or a“left” position as in FIG. 9E. The dragging of frame 932′ to the rightposition in FIG. 9D is equivalent to rotation of the prism to itsposition in FIG. 7A. The dragging of frame 932′ to the up position inFIG. 9E is equivalent to rotation of the prism to its position in FIG.8A.

As described in detail in PCT/IB2016/056060, in terms of imageacquisition, a user may press two-camera button 910 to simultaneouslyacquire two images, the Wide image of scene 106 at its respective(lower) image resolution and the Tele image of region (frame) 932 (or932′) at its respective (higher) image resolution. The two images may bestored in an on-board storage (such as “camera roll” in an iPhone) andmay be displayed or downloaded for further use as known in the art. Theuser may press single camera button 908 to acquire only the Wide image,which can further be stored, displayed and downloaded for further use.The user may choose for display on screen 902 only the Tele image by,for example, double-tapping or pressing at any point on the screenwithin frame 932 (or 932′). This action leads to display of the Teleimage on the entire screen. The Tele image (only) can then be chosen foracquisition by pressing on single camera button 908. The acquired Teleimage can then be stored, displayed and downloaded for further use asabove. The two images can also be fused (on the camera hosting device orin a cloud) into a composite image with a portion marked by a frame 932or 932′ formed by the higher-resolution Tele image, and with aperipheral portion formed by a peripheral portion of the relativelylower resolution Wide image.

Clearly, frame 932′ (and the Tele FOV) may be dragged to anyintermediate position (not shown) between the right and left positions.In other words, the Tele FOV may be moved laterally on the screen to anumber of partially overlapping or non-overlapping (but touching)positions, from a right-most position (at a right screen edge 940) to aleft-most position (at a left screen edge 942) or vice-versa, and anentire image of the scene may be “stitched” together from the partiallyoverlapping or non-overlapping Tele images. For example, as shown inFIG. 10, the ratio M of the Tele and Wide FOVs may be such that screen902 includes, and is substantially covered by, four adjacent frames932′a-d. Note that the screen may include fewer adjacent frames than thenumber required to substantially fill in the entire screen. For example,in an embodiment, there may be only two or three adjacent frames(instead of the four shown). An optional “Scan” icon or button 1002 maythen be used to scan (i.e. move the FOV_(T) frame) automatically from aright-most position on the screen (i.e. from frame 932′a) to a left-mostposition (i.e. to frame 932′d) or vice-versa. Alternatively, a “Scan”command may be given by voice control. The scan function, similarly tothe dragging action, provides partially overlapping or non-overlappingTele images that can be stitched together into a high-resolution Teleimage of the entire scene. A scan command, whether through icon 1002 orvocally, may also lead to acquisition of each Tele image defined by aframe 932′ and to its storage for further processing. A Wide image canbe captured during the scan function, allowing further processing thatmay include image fusion of the Wide image with the various Tele images(or the stitched Tele images) to form a high resolution image with a FOVthat is larger than FOV_(T).

Note that the direction of prism rotation and the consequent movement ofFOV_(T) relative to FOV_(W) on a smartphone (or any other host device)screen depends on the geometry of the assembly of the dual-aperturecamera in the host device. The description above relates to oneparticular such geometry. In a different geometry, the prism rotationdirections and the resulting FOV_(T) movement may be in oppositedirections to those described above.

The devices, used interface and associated methods disclosed above maybe used for automatic movement or “automatic adjustment” of the Tele FOVfor e.g. tracking a subject in an autonomous manner We refer to a cameramode that performs automatic Tele FOV movement to track an object orsubject of interest as “autonomous Tele FOV tracking”. The autonomousTele FOV movement is in response to recognition (through e.g. thesmart-phone camera) of the object or subject of interest, and the Teleimage focuses on and displays the object or subject of interest. Theobject recognition may be performed using any of the methods known inthe art. An example of autonomous Tele FOV tracking is shown in FIGS.11A-11C.

FIG. 11A shows a smartphone and user interface incorporating adual-aperture camera with automatic Tele FOV tracking disclosed hereinwith a first Tele FOV position on the smartphone screen. FIG. 11B showsthe smartphone and user interface of FIG. 11A with a second Tele FOVposition on the smartphone screen. FIG. 11C shows the smartphone anduser interface of FIG. 11A with a third Tele FOV position on thesmartphone screen. In each of these figures, the object of interest is arunner 1102. The decision to track the runner is taken either by theuser (e.g., by touching the runner's image) or automatically (e.g.,using face detection). It is assumed that the Tele camera can change itsFOV by tilting the prism to track the object of interest. Ideally, thecamera will track the object such that it is as close as possible to thecenter of the adjustable Tele FOV as seen in 1032 a, 1032 b and 1032 c.

While the smartphone shown in FIGS. 11A-11C displays icons 908, 910 and1002, one or more other icons (not shown) may replace and/or be used inaddition to or instead of icons 908, 910 and 1002 during operation inthe Tele FOV tracking mode.

Wide and Tele images and/or video streams can be recorded during theautomatic tracking mode and fused together to form a composite image orcomposite video stream. This fusion can be applied on the camera hostingdevice or alternatively, Wide and Tele images or video streams can beuploaded to the cloud for applying this fusion operation. Each compositeimage may also be formed with FOV_(W) by scanning with the Tele camera,stitching a plurality of Tele images to provide a “stitched” Tele image,then fusing the stitched Tele image with the Wide image. This isadvantageous in that the Wide image captures the entire scenesimultaneously, while the Tele images to be stitched together areconsecutive, so one can overcome motion or occlusions in the scene ifrequired. The stitching of the Tele images and/or the fusion of thestitched Tele image with the Wide image may also be performed in acloud.

While this disclosure has been described in terms of certain embodimentsand generally associated methods, alterations and permutations of theembodiments and methods will be apparent to those skilled in the art.The disclosure is to be understood as not limited by the specificembodiments described herein, but only by the scope of the appendedclaims.

What is claimed is:
 1. A method for obtaining a high-resolution imageusing a digital camera comprising a Wide camera that provides a Wideimage with a Wide resolution and a Wide field of view (FOV_(W)), and afolded Tele camera that provides plurality of Tele images with a Teleresolution higher than the Wide camera resolution and with a Tele fieldof view (FOV_(T)) smaller than the FOV_(W), wherein the Wide cameraincludes a Wide lens with a Wide lens optical axis and a Wide imagesensor with a width W_(W) and a height H_(W), wherein the Tele cameraincludes a Tele image sensor with a width W_(T) and a height H_(T),wherein W_(W)>H_(W) and wherein W_(T)>H_(T), the method comprising: a)positioning H_(T) in parallel with the Wide lens optical axis and W_(W)in parallel with W_(T); b) capturing a first Tele image with the FOV_(T)at a first position within the FOV_(W); c) detecting an object appearingin the Wide image FOV; d) moving the FOV_(T) relative to FOV_(W) totrack the detected object.
 2. The method of claim 1, wherein the movingthe FOV_(T) relative to FOV_(W) to track the detected object includesmoving the FOV_(T) to track the object autonomously.
 3. The method ofclaim 1, further comprising incorporating the digital camera into a hostdevice having a user interface for operating the digital camera.
 4. Themethod of claim 3, wherein the host device is a smartphone.
 5. Themethod of claim 1, further comprising, with the FOV_(T) positioned atthe first position within the FOV_(W), capturing a first Wide imagesimultaneously with the first Tele image.
 6. The method of claim 1,further comprising indicating the first Tele image by a frame visible ona screen of the digital camera, the frame showing and defining theFOV_(T).
 7. The method of claim 1, wherein the moving the FOV_(T)relative to the FOV_(W) includes moving the FOV_(T) relative to theFOV_(W) to obtain a plurality of additional Tele images with the FOV_(T)at respective additional positions within the FOV_(W).
 8. The method ofclaim 7, wherein at least some of the first Tele image and theadditional Tele images partially overlap each other.
 9. The method ofclaim 7, wherein at least some of the first Tele image and theadditional Tele images do not overlap each other.
 10. The method ofclaim 7, wherein the moving is performed manually.
 11. The method ofclaim 7, wherein the moving is performed automatically.
 12. A digitalcamera comprising: a) a Wide camera that provides a Wide image with aWide resolution and a Wide field of view (FOV_(W)); and b) a folded Telecamera that provides plurality of Tele images with a Tele resolutionhigher than the Wide camera resolution and with a Tele field of view(FOV_(T)) smaller than the FOV_(W), wherein the Wide camera includes aWide lens with a Wide lens optical axis and a Wide image sensor with awidth W_(W) and a height H_(W), wherein the Tele camera includes a Teleimage sensor with a width W_(T) and a height H_(T), wherein W_(W)>H_(W)and W_(T)>H_(T), wherein H_(T) is parallel with the Wide lens opticalaxis and W_(W) is parallel with W_(T), and wherein the digital camera isconfigured to capture a first Tele image with the FOV_(T) at a firstposition within the FOV_(W), to detect an object appearing in the Wideimage FOV and to move the FOV_(T) relative to FOV_(W) to track thedetected object.
 13. The digital camera of claim 12, wherein the digitalcamera configuration to move the FOV_(T) relative to FOV_(W) to trackthe detected object includes a configuration to move the FOV_(T) totrack the object autonomously.
 14. The digital camera of claim 12,wherein the digital camera is incorporated in a host device having auser interface for operating the digital camera.
 15. The digital cameraof claim 14, wherein the host device is a smartphone.
 16. The digitalcamera of claim 12, wherein the digital camera is configured to, withthe FOV_(T) positioned at the first position within the FOV_(W), capturea first Wide image simultaneously with the first Tele image.
 17. Thedigital camera of claim 12, wherein the digital camera is configured toindicate the first Tele image by a frame visible on a screen of thedigital camera, the frame showing and defining the FOV_(T).
 18. Thedigital camera of claim 12, wherein the digital camera configuration tomove the FOV_(T) relative to the FOV_(W) includes a configuration tomove the FOV_(T) relative to the FOV_(W) to obtain a plurality ofadditional Tele images with the FOV_(T) at respective additionalpositions within the FOV_(W).
 19. The digital camera of claim 18,wherein at least some of the first Tele image and the additional Teleimages partially overlap each other.
 20. The digital camera of claim 18,wherein at least some of the first Tele image and the additional Teleimages do not overlap each other.
 21. The digital camera of claim 18,wherein the configuration to move the FOV_(T) relative to the FOV_(W)includes a configuration to move the FOV_(T) manually.
 22. The digitalcamera of claim 18, wherein the configuration to move the FOV_(T)relative to the FOV_(W) includes a configuration to move the FOV_(T)automatically.